Art of making hub shells and the like



2, 1933- c. c. GROTNES ART OF MAKING HUB SHELLS AND'THE LIKE Filed June 15, 1929 2 Sheets-Sheet 1 J 6/2502 Caz/ 6. 570 65 y 2, 1933- c. c. GROTNES 1,906,578

ART OF MAKING HUB SHELLS AND THE LIKE Filed June 15. 1929 2 Sheets-Sheet 2 Patented Maj 2, 1933 1,906,578

OAR-L G. 6301118, PARK RIDGE, ILLINOIS mornmemsmrsm'rnnm Application l led June 18, 1989. Serial Io. 870,519.

The invention pertains to the manufacture, from sheet metal stock of relatively heavy gage, of wire wheel hub shells and similar annular objects; and the general aim of the invention is to reduce the cost of making such objects.

Hub shells and the like have heretofore been formed from sheet metal stock, and the method which is rhaps most commonly employed is to pro uce the article 1n the desired form by means of a series ofpunch press operations in which the metal is drawn from a flat sheet in the form of a disk. This method is objectionable because it involves a number of separate operations in large and expensive presses; because it involves a substantial waste of metal, in providing the blank disks; and because it necessitates an excessive drawing or stretching'of the metal frequently rupturing the same and thus producing a large amount of scrap, and furthermore resulting in hard spots as an incident to excessive stretching and so-called ironing of the metal. Such hard spots are especially objectionable inthe case of hub shells because they interfere seriously with the subsequent perforation of the shell to receive the spokes of the wheel.

With the foregoing objects in view, and further in view of similar difliculties encountered in other known methods of manufacg ture, the objects of my invention are to provide for the manufacture of hub shells and the like in a manner such as to reduce the waste of metal to a minimum; to minimize the number of operations: and to reduce the extent to which the metal must be stretched in order to form an annular object of substantial depth from a fiat sheet.

The objects of the invention thus generally stated are attained by first cutting an arcuate section from flat metallic stock, forming the same into a frusto conical ring, and then rolling the ring between opposed rolls so as to exert an external bending pressure on the central ortion of the ring in a direction substantially normal thereto while supporting the ends of the rin at spaced points, the rolls being appropriate y shaped to produce the desired curvature longitudinally of the ring as the latter is revolved between the rolls.

In the accompanying drawings I have shown, by way of exam le, my invention as carried out in the manu acture of hub shells for wire wheels, the formation of the shell being accomplished in two separate rolling operations a though the major part of the formation is accomplished in the first o ra' tion, the second being employed mere to pfi'olduce the desired shape for the ends 0 the s e Figure '1 of the drawings is a fra enta side view of two roll shafts with t lifa form ing rolls thereon shown in section and with the frusto conical rings from which the shell is formed shown in broken lines, the rolls occupying the relative positions which they assume at the end of the operation.

Fig. 2 is a fragmentary schematic view 9 illustrating the manner of forming a fiat strip of metal into a frusto conical ring.

Fig. 3 is a perspective view of the complete li ig. 4 is a fragmentary elevational view illustrating the final operation to shape the ends of the shell.

Fig. 5 illustrates one manner of providing arcuate strips with a substantially negligible waste of the sheet stock.

Figs. 6 and 7 illustrate another method of providing the arcuate strips, being respectively an end and an end view of a spiral formed from an elongated strip of metal and having a curvature such that relatively flat 5 segments of proper length may be cut without wasting any metal stock.

Referring now with more particularity to my improved method of manufacture, the first step in the process is to form the arcuate segments from which to make frusto conical rings of substantial length or depth. For this purpose arcuate blanks 8 may be cut as shown in Fig. 5, from a flat sheet of metal 9.

In this event the sheet 9 is initially cut of a width conforming to the maximum overall length of the segments 8, and it will be observed that only a small amount of flat metal stock is not used. Or the se ents may be cut from a spiral strip 9" suc as shown on a small scale in Figs. 6 and 7 each convoluin the art. After the segment is thus shaped,

the ends are brought together and permanently united, as by welding, to form a frusto conical ring 13 (Fig. 3).

The ring thus formed is laced between two forming rolls 14 and15 Fi 1) 'res ectively mounted on shafts 16 an 17. These shafts and rolls may form part of a rolling machineof any suitable or preferred character. For example it may be of the general type shown in my copending application Serial No. 18,949, filed March 28,1925, with the exception that the shafts 16 be mounted at an angle with respect to the shaft 17 in conformance with the generally conical character of the article to be produced. As in said copending application, the lower roll shaft may be mounted for movement toward and away from the upper shaft with revision for driving both shafts during the forming operation.

When the lower forming roll 14 is withdrawn from the upper roll 15, the blank 13 may be inserted between them as shown in broken lines in Fig. 1, the position of the blank endwise of the roll being determined by a suitable gage (not shown) as is customary in the metal-rolling art. The lower forming roll it will be observed has a reduced intermediate portion 18 and relatively enlarged end portions 19 and 20, the latter being substantially larger. Conversely the upper forming roll has an enlarged intermediate portion 21 and reduced end portions 22 and 23. Thus the surfaces of the forming rolls are substantially complementary.

It will beseen that when the ring 13 is initially positioned between the rolls, the ends thereof are supported upon the enlargements 19, 20 of the lower roll: and as the rolls come together, external pressure is exerted on the intermediate ortion of the ring in a direction substantially normal to the surface of the ring which is being acted upon. As a result the central portion of the ring is bent inwardly into approximately V-form to produce a reduced intermediate portion 24 approximately parallel to the axis of the inner roll, and an annular portion 25 approximately at right angles to such axis. At the same time the ends of the rolls coact to shape the end portions 26 and 27, these latter end portions being of rounded formation with the former inturned inwardly with a reverse bend at the smaller end of the ring.

It will be observed that by reason of the initial formation of the blank into a frusto :metal stock r tial waste, an

conical ring and further by reason of the exertion of the bending pressure centrally of the in a direction substantially normal to the ace of the latter, the metal is shaped without unduly stretching or ironing the same. 'At the same time itwill be ap arent that the end portion 27 resulting, is o a diameter substantially eater than the intermediate portion 24. e other end portion 26 is only slightly greaterin diameter than the intermediate rtion 24.

The operation illustrated in Fi 4 is in character a finishing operation. us the work after having been formed as above set forth in connectionwith Fig. 1 may be submitted to a second operation between rolls 28 and 29 shaped to operate more especially on the end portions 26 and 27 so as to form an mturned 11 e 30 at the smaller end and an axially exten ing flange 31 at the larger end.

The'cost of manufacturing hub shells accordin to my invention is substantial] less than with methods heretofore employe primarily because the operation may be per formed in much less time and by means of equipment much less expensive to roduce and maintain. Also practically a of the uired is used without substanthe resulting roduct is superlor because of the absence 0 hardness due to excessive stretching and ironing.

I claim as my invention:

1. The method of making hub shells or similar annular ob'ects which consists in rolling a ring of usto conical form between opposed rolls while exerting pressure on the ring in a direction substantially normal to the face thereof whereby to form an intermediate portion of reduced diameter and an sped portion of substantially greater diame r.

2. The method of making hub shells or similar annular objects'of substantial depth, which includes first forming a frusto conical ring from sheet metal stock, and then shaping the ring by supporting the ends thereof and exerting pressure midway between its ends in a direction normal to the face of the ring to bend the intermediate portion of the ring approximately into V-shape with one leg of the V dis (1 substantially perpendicular to the ot er leg.

3. The method of making hub shells and similar annular objects which consists in rollin a frusto conical ring between two opposed ro lers to change its contour in a direction longitudinally thereof whereby to form an intermediate portion of reduced diameter with enlarged end portions, andthen rolling the ring thus formed to form end flanges on said end portions, one extending transversely of the axis of the work and the other longitudinally thereof.

4. The method of making hub shells or Similar annular articles which consists in forming from sheet metal stock a. blank of arcuate form, bending the arcuate blank into a ring of frusto-conical form and permanent- 1y uniting the ends thereof, and rolling the ring between opposed rollers while exerting bending pressure on the ring in a direction substantially normal to the face of the rin In testimony whereof, I have hereunto a fixed my signature.

CARL c. GROTNES. 

